| Diet | Herbivore |
| Height | 1.2m |
| Length | 4m |
| Weight | 200 kg |
| Speed | 25 km/h |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Ornithopod |
| Location | North America |
Thescelosaurus was a medium-sized ornithopod dinosaur that lived during the Late Cretaceous period, between 93.9 and 72.2 million years ago. This herbivorous dinosaur inhabited the western regions of North America, where it thrived in the diverse ecosystems of the time. Despite its name meaning 'wonderful lizard', Thescelosaurus was initially overlooked by palaeontologists, which led to its species name 'neglectus'.
This ornithopod measured approximately 4 metres in length and stood about 1.2 metres tall at the hip, weighing around 200 kilograms. Thescelosaurus had a relatively robust build compared to other ornithopods of its size, with strong hind legs that suggest it was capable of reaching speeds of up to 25 kilometres per hour when escaping predators. Its body was well-adapted for a bipedal lifestyle, though it could likely move on all fours when feeding.
As a herbivore, Thescelosaurus fed on a variety of plant material available in its Late Cretaceous environment. Its teeth were well-suited for processing tough vegetation, including ferns, cycads, and early flowering plants. The dinosaur's jaw structure allowed for efficient chewing, helping it extract maximum nutrition from the plant matter it consumed.
Thescelosaurus represents an important example of ornithopod diversity during the final stages of the Mesozoic Era, living alongside famous dinosaurs like Triceratops and Tyrannosaurus rex in the closing chapter of the age of dinosaurs.
Thescelosaurus had a relatively stocky build for an ornithopod, with robust hind legs and a moderately long tail. Its skull was proportionally large with a distinctive beak-like front end, and it possessed small but effective teeth for processing plant material.
Thescelosaurus likely lived in small herds or family groups, using its keen senses and speed to detect and escape from predators. Evidence suggests it was primarily active during daylight hours, spending much of its time foraging for suitable vegetation in the diverse Late Cretaceous landscapes.
Thescelosaurus was first described by Charles W. Gilmore in 1913. The original fossils were discovered at Western North America.
